Bias and runs in dice throwing and recording: A few million throws

An experimenter threw individually 219 different dice of four different brands and recorded even and odd outcomes for one block of 20,000 trials for each die—4,380,000 throws in all. The resulting data on runs offer a basis for comparing the observed properties of such a physical randomizing process with theory and with simulations based on pseudo-random numbers and RAND Corporation random numbers. Although generally the results are close to those forecast by theory, some notable exceptions raise questions about the surprise value that should be associated with occurrences two standard deviations from the mean. These data suggest that the usual significance level may well actually be running from 7 to 15 percent instead of the theoretical 5 percent.The data base is the largest of its kind. A set generated by one brand of dice contains 2,000,000 bits and is the first handmade empirical data of such size to fail to show a significant departure from ideal theory in either location or scale.The analysis was facilitated by a National Science Foundation grant GS-341 and and its continuation GS-2044X. It forms part of a larger study of data analysis.Mr. Longcor is from Waukegan, Illinois; the other authors are from Harvard University. Dr. Iversen has moved to the University of Michigan.     

The operant conditioning of conversation

Human conversation is a natural place to begin the study of social responses. In a conversation, a number of individuals use one another's responses as cues for their own behavior. So long as a conversation is being held, the speakers must talk in some order. Four experiments were conducted to test whether differentially reinforcing a group of speakers can bring the order of speakers under experimental control. The results are all consistent with the hypothesis. The paper also devises and evaluates different procedures for studying conversational sequences and examines associated statistical problems.     

Electrodermal responses to movie stressors: Nicotine × extraversion interactions

Support was found for Eysenck's hypothesis that the effects of smoking sized doses of nicotine on cortical and electrodermal activity are functions of extraversion and the degree of externally-induced arousal. Responses to scenes that elicited moderate electrodermal and emotional responses followed the predicted extraversion ☆ nicotine interaction for electrodermal measures, but not for self-reported emotions, heart rate or electromyographic measures. The failure of the Ss to demonstrate an extraversion ☆ nicotine interaction when high-intensity stimuli were used (Gilbert and Hagen, 1980) is also interpreted as consistent with Eysenck's hypothesis.